Prognostic factors in uterine sarcoma: A clinicopathologic and immunohistochemical (IHC) study of 30 cases

Abstract

16071 Background: The objective of this study is to examine the prognostic relevance of traditional clinical, pathological and IHC features of uterine sarcoma (US). Methods: The study population consisted of thirty cases of US treated at our institute. Twenty- two cases are HGS (11 leiomyosarcoma, and 11 carcinosarcoma) and eight cases are LGS (5 mullerian adenosarcoma and 3 low grade endometrial stromal sarcoma). Clinical and pathological data including patient's age, parity, menopausal status, tumor cell type, lymphovascular invasion, nuclear grade, stage and mitotic index. Serial sections were immunostained with antibodies for p53, bcl-2, estrogen receptor (ER), Her2 and c-kit. The clinicopathological and IHC features were analysed by using Kaplan-Meier method for constructing survival curves, and log-rank statistic for survival curves comparison. Multivariate analysis was performed using Cox regression modeling. Results: The mean follow-up period of patients is 32 months (range 1- 120). Twelve (55%) patients with HGS died of the disease and none of the LGS group. In the HGS group, stage (p=0.01), myometrial invasion in early stage tumor (p=0.04), and lymphovascular invasion (p=0.043) were significant predicators of patient outcome in univariate analysis. Similarly, tumor cell type, ER, p53 and bcl-2 expression showed statistical significant correlation with tumor-specific survival (p=0.0039, p=0.001, p=0.03, and p=0.04, respectively). ER and bcl-2 expression were associated with better outcome and the opposite for p53 expression. In a multivariate analysis, only the tumor stage and cell type had independent statistical significance (p=0.04, and p=0.035, respectively). Overexpression of p53 and Her2 were observed in 40% and 60% of carcinosracomas respectively and not seen in any of the other tumors. The c-kit immunostain showed focal and weak staining in 40% of carcinosarcoma and only in 33% of leiomyosarcoma. None of LGS had this marker. The ER was expressed only in the LGS group. Conclusions: This study demonstrates that stage and tumor cell type are the most important prognostic indicators of patient outcome in US. IHC markers such as ER, p53, c-kit, and Her2 can be useful ancillary tools to discriminate between HGS and LGS in difficult cases. No significant financial relationships to disclose.